Research in prostate cancer

We are always learning more about cancer. Researchers and healthcare professionals use what they learn from research studies to develop better practices that will help prevent, find and treat prostate cancer. They are also looking for ways to improve the quality of life of people with prostate cancer.

The following is a selection of research showing promise for prostate cancer. We’ve included information from PubMed, which is the research database of the National Library of Medicine. Each research article in PubMed has an identity number (called a PMID) that links to a brief overview (called an abstract). We have also included links to abstracts of the research presented at meetings of the American Society of Clinical Oncology (ASCO), which are held throughout the year. You can find information about ongoing clinical trials from CanadianCancerTrials.ca and ClinicalTrials.gov. Clinical trials are given an identifier called a national clinical trial (NCT) number. The NCT number links to information about the clinical trial.

Preventing prostate cancer

Some substances or behaviours may prevent prostate cancer or lower your risk of developing it. The following is noteworthy research into ways to prevent prostate cancer or lower your risk.

Acetylsalicylic acid (ASA, Aspirin, salicylate) and other nonsteroidal anti-inflammatory drugs (NSAIDs) lower prostate-specific antigen (PSA) levels (European Journal of Cancer, PMID 25727881). Research shows that men taking Aspirin or another type of NSAID or both have a lower risk of developing prostate cancer (Clinical Cancer Research, PMID 25520389). More research is needed to support these findings.

Lycopene is a type of carotenoid that gives red vegetables and fruits their colour. Recent reviews and meta-analyses (large research studies that look at the results of several individual studies) looked at lycopene research. They suggest that men who take in higher amounts of lycopene from their diet have a lower risk of developing prostate cancer (Prostate Cancer and Prostatic Diseases, PMID 28440323; Medicine, PMID 26287411). More research is needed to understand how lycopene may lower the risk of prostate cancer or if substances can be combined with lycopene to reduce the risk.

Screening

Screening tests help find prostate cancer before any signs or symptoms develop. When cancer is found and treated early, the chances of successful treatment are better. The following is noteworthy research into screening for prostate cancer.

The Stockholm 3 Model (STHLM3) combines personal factors and several tests, including the PSA test. Researchers are looking at STHLM3 as a way to screen for prostate cancer. A recent study found that it can identify men who have a higher risk for prostate cancer, which can lower the number of biopsies done to look for prostate cancer (Lancet Oncology, PMID 26563502; European Urology Focus, PMID 28753803). Further study is needed to find out the exact role STHLM3 may have in screening for prostate cancer.

Prostate-specific antigen velocity (PSAV) measures changes in the level of PSA over time. The IMPACT clinical trial used PSAV in men with a known genetic risk for developing prostate cancer. Results suggest that men whose PSA levels change by more than 0.75 ng/mL over a year have a higher risk of developing prostate cancer. The trial also found that men with BRCA gene mutations and an increase in PSA levels had an even higher risk of developing prostate cancer than men with other genetic risk factors. The IMPACT trial also found that PSAV could predict which tumours would have a Gleason score of 7 or higher (ASCO, Abstract 16). Recent research has not seen the same benefit of using PSAV to predict the risk for developing prostate cancer (British Journal of Cancer, PMID 29301143).

Diagnosis and prognosis

A key area of research looks at better ways to diagnose and stage prostate cancer. Researchers are also trying to find ways to help doctors predict a prognosis (how likely it is that the cancer can be successfully treated or that it will come back after treatment). The following is noteworthy research into diagnosis and prognosis.

Biomarkers are substances, such as proteins, genes or pieces of genetic material like DNA and RNA, that are found naturally in the body. They can be measured in body fluids like blood and urine or tissue that has been removed from the body. A gene mutation or a change in the normal amount of a biomarker may mean that a person has a certain type of cancer. Biomarker tests that look for changes in certain biomarkers can help your doctor decide if a biopsy is needed to diagnose prostate cancer. Biomarker tests can also help doctors determine the risk of prostate cancer recurrence, and predict the prognosis or response to treatment. Researchers are looking at the following biomarker tests to see if they can help doctors diagnose, assign a risk level to, predict a prognosis for and find out which treatments will benefit a man with prostate cancer:

MRI ultrasound fusion–guided biopsy combines MRI and ultrasound to make very detailed 3D pictures of the prostate from many different angles (called a multiparametric image). The detailed images help doctors target specific areas in the prostate to take biopsy samples. Research shows that this type of diagnostic test helps find prostate cancer early (BioMed Research International, PMID 29094042; Central European Journal of Urology, PMID 27123316).

Treatment

Researchers are looking for new ways to improve treatment for prostate cancer. Advances in cancer treatment and new ways to manage the side effects from treatment have improved the outlook and quality of life for many people with cancer. The following is noteworthy research into treatment for prostate cancer.

Radiation therapy

Researchers are looking at new and better ways to deliver radiation therapy. They are also trying to find out if radiation can be combined with other treatments to make them both more effective.

Hormonal therapy

Hormonal therapy is often used to treat prostate cancer. Researchers are looking for new hormonal therapy drugs and the best way to use them to treat prostate cancer.

ODM-201 (darolutamide) is a new type of drug that lowers the amount of androgen in the body. The ARAMIS clinical trial is a large international trial that is trying to find out how safe and effective ODM-201 is at preventing high-risk prostate cancer from spreading to other parts of the body (ClinicalTrials.gov, NCT02200614). The ARASENS clinical trial is looking at ODM-201 in combination with standard hormonal therapy (androgen deprivation therapy, or ADT) and docetaxel (Taxotere) to treat metastatic prostate cancer (ClinicalTrials.gov, NCT02799602).

Chemotherapy

Researchers are looking at new drugs to treat prostate cancer. They are also trying to find out if chemotherapy can be combined with other treatments to make them more effective.

Custirsen is a drug that stops the production of the protein clusterin, which helps prostate cancer cells become resistant to treatment. Research suggests that combining custirsen with chemotherapy may help improve survival in men with prostate cancer that has stopped responding to hormonal therapies (called castrate-resistant cancer). Recent clinical trials have not shown that custirsen improves survival (Lancet Oncology, PMID 29033099, PMID 28283282).

The combination of chemotherapy, hormonal therapy and radiation therapy was compared to hormonal therapy and radiation therapy as treatment for cancer that had not spread outside the prostate (called localized cancer) but that had a high risk of recurring. The chemotherapy drugs used were docetaxel and prednisone. Results suggest that adding chemotherapy to hormonal therapy (ADT) and radiation therapy improved overall survival. More research and longer follow-up is needed to confirm these results (ASCO, Abstract LBA5002).

Docetaxel and zoledronic acid (Zometa), a type of bisphosphonate, may be treatment options for men who are starting hormonal therapy for prostate cancer. The STAMPEDE trial compared 3 groups. When starting hormonal therapy, the first group was given docetaxel, the second group was given zoledronic acid and the third group was given both drugs. The study showed that giving docetaxel at the start of hormonal therapy significantly improved survival, but adding zoledronic acid did not (Lancet, PMID 26719232).

Immunotherapy

Researchers are developing and testing immunotherapies to find more effective ways of treating prostate cancer.

Cancer treatment vaccines may be a treatment option for castrate-resistant prostate cancer that has spread to other parts of the body. Researchers are developing several vaccines and studying them in clinical trials. These vaccines include PROSTVAC and DCVAC/PCa (ASCO, Abstract TPS5070, Abstract TPS5081; Future Oncology, PMID 26235179).

Immune checkpoint inhibitors are drugs that work by blocking specific proteins (called checkpoints) so immune system cells can attack and kill the cancer cells. Research shows that the immune checkpoint inhibitor ipilimumab (Yervoy) didn’t improve overall survival in men with metastatic castrate-resistant prostate cancer, but it is linked with prolonged progression-free survival. More research is needed to find out if ipilimumab could be combined with other treatments to help improve overall survival (Journal of Clinical Oncology, PMID 28034081).

Ablation therapy

Ablation therapy is a procedure that removes or destroys cells or tissues with heat, chemicals or other techniques. Research is looking at different types of ablation therapy that can be used instead of surgery for early prostate cancer.

Cryosurgery uses extreme cold (liquid nitrogen or carbon dioxide) to freeze and destroy abnormal cells or tissue. One study looked at using cryosurgery as the main treatment for prostate cancer that has not spread outside of the prostate. Results suggest that cryosurgery can provide long-term control of the cancer and may be a treatment option for some men (ASCO, Abstract 114). Cryosurgery may also be an option for men with prostate cancer that comes back in the same area that it started (Prostate, PMID 25283814).

High-intensity focused ultrasound (HIFU) uses concentrated high-frequency sound waves to heat up and destroy tissues. Researchers are looking at HIFU as a treatment for prostate cancer. They are comparing HIFU to standard treatments to see if it is a safe and effective treatment option (Journal of Urology, PMID 28433640; Progrès en Urologie, PMID 26476975; Advances in Urology, PMID 26357511; ASCO, Abstract 109).

Learn more about cancer research

Researchers continue to try to find out more about prostate cancer. Clinical trials are research studies that test new ways to prevent, detect, treat or manage prostate cancer. Clinical trials provide information about the safety and effectiveness of new approaches to see if they should become widely available. Most of the standard treatments for prostate cancer were first shown to be effective through clinical trials.

A protein made by the prostate that is normally found in the semen and blood. Higher amounts of PSA may be found in the blood of men who have prostate cancer, benign prostatic hyperplasia (BPH) or inflammation of the prostate.

PSA can be used as a tumour marker. It is used to monitor a man’s response to treatment for prostate cancer, or to see if prostate cancer has come back (recurred) after treatment.

carotenoid

A yellow, orange or red substance found mostly in plants, including yellow and orange fruits and vegetables (such as carrots and sweet potatoes), as well as in dark green, leafy vegetables (such as spinach and kale) and some grains. The body changes some carotenoids into vitamin A.

Carotenoids include beta carotene, lutein and lycopene.

Carotenoids are a type of phytochemical that have antioxidant effects. Researchers are studying the role of carotenoids in preventing cancer.

BRCA gene mutations

BRCA1 and BRCA2 genes are tumour suppressor genes. Changes to genes are called mutations. Mutations of the BRCA genes are inherited from one or both parents, and these mutations increase the risk of cancer.

Women with BRCA mutations have a higher risk of breast and ovarian cancers. Men with BRCA mutations also have a higher risk of breast cancer, and may have a higher risk of prostate cancer. The risk of other cancers – such as stomach or pancreatic cancer – may also be higher with BRCA mutations.

Gleason score

A system used to describe the grade of prostate cancer based on how the cancer cells look and behave when viewed under a microscope.

When examined under a microscope, prostate cancer cells can be classified with different grades (from 1 to 5). The pathologist examines a sample of prostate tissue and determines the first and second most common grades in the sample. These grades are added to determine the Gleason score. The prostate cancer is assigned to 1 of 3 risk groups (low, intermediate and high) based on the Gleason score.

Also called Gleason classification or Gleason scale.

stage

A description of the extent of cancer in the body, including the size of the tumour, whether there are cancer cells in the lymph nodes and whether the disease has spread from its original site to other parts of the body.

Stages are based on specific criteria for each type of cancer.

The process of determining the extent of cancer in the body based on exams and tests is called staging.

biopsy

The removal of cells or tissues for examination under a microscope.

Different types of biopsies include incisional biopsy, excisional biopsy and needle biopsy. Sometimes imaging techniques are used to guide the biopsy, as in ultrasound-guided biopsy and computed tomography (CT)–guided biopsy.

androgen

A type of hormone that regulates the growth, development and function of the male reproductive system (the group of organs involved in having children). Androgens also control the development of male physical traits, such as deep voice and the growth of body and facial hair, and increase muscle and bone strength.

The main androgen is testosterone, which is made mainly in the testicles.

progression-free survival

The amount of time after treatment that a person lives with a disease (such as cancer) without the disease getting worse.

Researchers may measure progression-free survival in clinical trials to find out how well a treatment works.